The present invention relates in general to surface modification and measurement techniques and apparatus, and in particular to techniques and apparatus for modifying and measuring surfaces of diamond or other workpieces to nanoscale precision.
Ball bearings are conventionally made of metal or ceramic materials that can be finished to a surface smoothness with deviations on the order of tens of nanometers. Standard methods for making ball bearings include using a stamping machine to cut a ball from a wire of metal or ceramic material, then rolling the ball between plates to smooth over the rough edges left from the stamping procedure. For other applications, hollow capsules are made from glass microballoons or from hollow cylindrical wires, in much the same fashion as ball bearings. Surface roughness or smoothness is imposed by laser ablation, and surface deviations of a few nanometers to tens of nanometers, depending on the hardness and integrity of the material, are typical.
There is also interest in making ball bearings, hollow capsules and similar structures out of other materials that will allow surface finishes to a higher precision and that will also be suited for use at extreme temperatures (e.g. near absolute zero and/or above 100 K), or where extreme demands are placed on the strength and uniformity of the ball bearing or capsule. It is also sometimes desirable to provide surfaces having small-scale features (e.g., ridges, grooves or the like), and such features should be formed with micrometer or nanometer precision.
It would therefore be desirable to provide apparatus and techniques for measuring surface quality and for shaping surfaces to micrometer (μm) or nanometer (nm) precision.